Baking Pan Size Converter

Use this converter! Enter your round pan's diameter and height as the "Original" pan, then select square and enter the square pan's side length and height as the "Target." The tool calculates the volume ratio automatically. For example, an 8-inch round pan (≈101 cu in) is roughly equivalent to a 7-inch square pan (≈98 cu in at 2″ depth). An 8-inch round pan holds about 79% of the volume of an 8-inch square pan, so you'd multiply your recipe by approximately 1.27× to use an 8-inch square pan instead.

Round pan: Volume = π × (diameter ÷ 2)² × height. For example, an 8″ round pan at 2″ depth: π × 4² × 2 = π × 16 × 2 ≈ 100.5 cubic inches.

Square pan: Volume = side × side × height. An 8″ square pan at 2″ depth: 8 × 8 × 2 = 128 cubic inches.

Rectangle pan: Volume = length × width × height. A 9×13″ pan at 2″ depth: 13 × 9 × 2 = 234 cubic inches.

The conversion ratio is simply: Target Volume ÷ Original Volume. Multiply all recipe ingredients by this ratio.

Yes! Two 8-inch round pans (each ~101 cu in at 2″ depth) total about 202 cubic inches. A 9×13-inch pan at 2″ depth holds about 234 cubic inches. The ratio is 234 ÷ 202 ≈ 1.16, so you'd multiply your recipe by about 1.16× (or roughly add an extra 15% of ingredients). The batter will be slightly thicker in the 9×13 pan, so you may need to increase baking time by 3–5 minutes.

Generally, if your new pan results in a thicker batter layer (deeper pan or smaller surface area), lower the oven temperature by 10–15°F (5–8°C) and extend baking time. Thicker batters need more time for the center to bake through without burning the edges. Conversely, if the batter is spread thinner (larger pan), the center bakes faster—check for doneness 5–10 minutes earlier. Always rely on visual cues and the toothpick test rather than strict timing.

Cakes can sink when the batter depth changes significantly. If your new pan creates a much deeper batter layer, the center may not set properly before the leavening agents lose their lift, causing collapse. Additionally, if you scale up a recipe dramatically (3× or more), chemical leavening (baking powder/soda) doesn't always scale linearly. For large volume increases, consider baking in batches or using multiple pans of the original size for best results.

For ratios that aren't easy fractions, here are practical strategies:

• Eggs: Use the ratio as a guide for eggs—1.37 × 3 eggs = 4.11 eggs, so use 4 eggs (rounding is usually fine for ±1 egg equivalent).
• Flour/Sugar: Weigh ingredients with a kitchen scale for precision; multiply gram amounts directly by the ratio.
• Small amounts: For salt, spices, and leavening agents, round to the nearest convenient measure (¼ tsp, ½ tsp, etc.).
• Alternative: Make the full original recipe plus an extra half-batch (1.5× total) to get close, accepting slightly thicker or thinner layers.

Specialty pans like Bundt pans, tube pans, and springform pans have complex geometries, but you can approximate their volume using water displacement: fill the pan with water, then measure how much water it holds (in cups or milliliters). Enter the closest basic shape in the converter with dimensions that match your measured volume. A standard 10-cup Bundt pan holds about 144 cubic inches (2,360 ml), roughly equivalent to a 9-inch round pan at 2.25″ depth. Many Bundt pan recipes are specifically formulated for that shape's volume, so always check the recipe notes!

Absolutely! Depth dramatically affects volume. An 8-inch round pan at 1.5″ depth holds ~75 cu in, while the same pan at 3″ depth holds ~151 cu in—double the volume. Always measure your pan's actual depth (not just what the label says). Most standard cake pans are 2 inches deep, but springform pans can be 2.5–3 inches, and sheet pans are often only 1 inch deep. Small depth differences can significantly impact your conversion accuracy.